Membrane Transport/Cell Junctions

plasma membrane

selectively permeable; allowing some things to go through and others not

passive transport

does not require the use of ATP

plasma membrane

selectively permeable; allowing some things to go through and others not

passive transport

does not require the use of ATP

active transport

requires the use of ATP

filtration

particles are driven through the membrane by physical pressure

simple diffusion

net movement of dissolved particles down their concentration gradient

osmosis

net flow of water through selectively permeable membrane (pulls/draws water)

osmotic pressure

the "pulling" force

hydrostatic pressure

the "pushing" force

reverse osmosis

process of applying mechanical pressure to override osmotic pressure

osmolarity

number of osmoses per liter of solution

hypotonic solution

causes cell to absorb water and swell

hypertonic solution

causes cell to lose water and shrivel

isotonic solution

causes no change in cell volume

facilitated diffusion

carrier moves solute down its concentration gradient; does not use ATP

primary active transport

carrier moves solute through a membrane up its concentration gradient

vesicular transport

moves large particles, fluid droplets, or numerous molecules at once through the membrane in vesicles

exocytosis

discharging material from the cell

endocytosis

vesicular processes that bring material into cell

phagocytosis

Cell eating

pinocytosis

Cell drinking

receptor-mediated endocytosis

particles bind to specific receptors on plasma membrane

transcytosis

transport of material across the cell by capturing it on one side and releasing it on the other